IDE Options dialog:
Editor->Completion and Hints->
uncheck "Add close statement for pascal blocks"
Also, this wouldn't be a problem if code is properly indented. For example
if case1 then begin
if case2 then begin
DoSomething;
end;
end;
end; // Indented on same position as upper line, so you know it is extra.
Also if you place cursor on word "begin", it will show rectangle highlight on the matching "end" to it.